Releasing clamp



Nv. 24, 1931. J, M, ESTER 1,833,578

RELEAsNG CLAMP Filed Sept. 20. 1928 2 Sheets-Sheet 1 Nov. 24, 1931.- J'. M. JESTER 1,833,578

-RELEASING CLAMP Filed Sept. 20, 1928 2 Sheets-Sheet 2 FIG' 5 35- daim Milf@ Patented Nov. 24, 1931 PATENT OFFICE JOHN MILTON JESTER,-OF WASHINGTON, DISTRICT OF COLUMBIA RELEASING CLAMP Application led September 20, V1928.

The invention relates to clamps intended to be used at the lower end of a string of insulators for supporting a conductor employed in high tension line service.

.5' It is well known that in conducting high voltagesfor comparatively long distances it is customary to employ supporting towers at quite an appreciable distance apart, these towers being equipped with strings of insulators carrying some sort of clamp holding the conductor. Under variations in climatic conditions at different areas, and particularly at different sides of a mountain, oothill or the like, it vfrequently occurs that sleet or ice accumulates upon the conductor, resulting in a greatly increased Weight which tends to pull to one side the lstring of insulators at a paiticulaitowei'. This strain may, in actual practice, be so great as to topple over'the tower or deform it in some respect. As the result of this condition which may exist and which has ybeen frequently found to occur, I have devised the present invention which has for its general'object the provision of a conductor supporting clampwhich is capable of releasing the conductor upon the occurrence of anunusual stra-in upon one side thereof so that the conductor may slip through and permit ythe strains to become equalized or uniformly distributed. A Y

Y AnV important object of the invention is to provide a clamp of this type which will Vmaintain its holding action notwithstandr ing longitudinal movement of the conductor for a limited extent, it being a distinct feature that the clamp will not release the conductor until movementthereof has exceeded a certain predetermined amount.

Another object of the invention is to provide a suspension clamp having cam means for positively e'ecting separation of the clamping elements which normally engage theV conductor so that no reliance needvbe r:

placed upon the tension of the conductor or its' tendency to resume a practically straight line-position such as would benecessary under some circumstances orin connection with certain devices for this general purpose.

Still another object of the invention, and

Serial No. 307,138.

an important one, is to provide a clamp which embodies the minimumnumber of parts, only three in fact aside from bolts and nuts, namely a suspension element and counterpart clamping members having coacting means thereon for certain purposes.

A still further object of the invention is to provide a conductor suspension clamp equipped with means whereby its tension or gripping action upon the conductor may be varied at the will of the installer, this means permitting adjustment to take up any wear which might occur after protracted use.

Yet anotherobject is to provide a clamp which,lif released upon the occurrence of an unusual strain, will be capable of resuming its grip or clamping action upon a conductor upon the cessation of the force operating to effect the initialrelease.

An additional object of the invention is to provide a releasing clamp of the character mentioned which will be very simple and inexpensive to manufacture, easy to install, positive in action, efficient and durable in service, and a general improvement in the art.

To the attainment of the foregoing and other objects and advantages, the invention preferably consists in the details of construction and the arrangement and combination of parts to be hereinafter more fully described and claimed, and illustrated in the accompanying drawings in which:

Figure 1 is aside elevation of a clamp constructed in accordance with the invention, showing it in fits normal or cable gripping position or condition,

Figure 2 is an end elevation thereof,

Figure 3 is a central vertical cross sectional view,

Figure 4 is a side elevation showing a modification in which means is provided for adjusting purposes,

Figure 5 is a central vertical cross sec-k tional view therethrough, and

Figure 6 is a fragmentary side elevation showing the means for preventing relative longitudinal movement of the clamping members.

Referring more particularly to the draw# ings, I have shown the device as comprising Va pair of complementary clamping members as counterparts, Each of these membersis formed with a channeled seat 3y adapted to engage against the conductor 4 which be stranded or otherwise, this detail 'being iinp y g tion disclosed in Figures V1 to 3 inclusive,

material. Both of these members are some* what elongated in' actual Ypractice and have;

flaring ends to avoid bringing any abrupt bending strainsupon.the-conductor; ln order to prevent relative longitudinal movement of` these members, some means must be provided and in theV present'instance this means is shown as comprising lugs 5 on each member fitting between pairs of lugs o on the other.'Y Itis of course immaterial as to the exactarrangement of these lugs but by formvingthem in the particular locations disclosed it is apparent that the members 1 and 2 may be reversed end forv end as may be found desirable in actual practice. i

The suspension means is here shown as comprising a pair of links 7 adapted to be n connected with the lowermost unit of a string 'of insulators regardless of the type thereof,

Y apertured at theirupper ends at 8 for engagement therethrough of a pin-9 c :onnected with a c'levis type of suspension means vat the lower Vend ofa string of insulators. However, other found advisable.

variations are'readily apparent. .y f v The invention contemplates th'eprovisions of means, particularly `cam means, whereby the members 1 and 2 will be held norm ally in clamping engagement upon the conductor 4 and also cam means for releasingthisengaga ment upon thel occurrenceA of Yan unusual strain at lone side or the other of a string of insulators from which-the clamp, and the conductor, maybe suspended. p v

Even though quite al number of modifications might be suggested, it is preferable that the links 7 lbe provided, intermediate their ends, with laterally enlarged portion-s1 10 formed with c'ai'n slots 11V for a purpose to be described. It is intended that the pair of links 7 be pivoted with respect to the lower clamping *member 2 andr I have therefore illustrated a bolt 1,2 passing through holes 13 in the links, through a hole' 14 in'the lower clamping member, and equipped with a sin- Ofle nutl which may be cottered or not,l as

. ln order to effect connection 'withth'e upper clamping member, I. provide bolt 16 whichl passes through a hole 17 in the upperclainp! ingmember 1 and throughY the f cani "slots 11,

this bolt being likewise cottered if preferred.

It should be pointed out that the cam slots 11 in the enlarged portions 10 of the suspension links are of p'eculair shape inasmuch as each has a surface 18 concentric with the bolt '12 and otherv portions, 19 which are revers'elycurved with respect thereto V-a's clearly indicated in Figure 1, and also n Figure 4 thoughthis latter figure will beliereinafter ,described in greater detail;

ln the `roperation of the formof the invenit will be seen that installation of the clamp upon the conductor may be eected while the suspension links 7 are at an angular position with respect to the members 1 and y2 so that the bolt 16 will bena-tl one" end or the. other of the cam slots 19. llilhen this bolt 16l is: in

this'position it will be apparenttlijatthere 1 tion ofthe slot 11,jand as this intermediate lportion is concentric with the bolt 12 itis apparent that afirm clamping'action .-upon the conductor 4 isobtained. Y

Y' In service, it will be clear that if the clamp y.should inov'e withA the conductor to alimited vextent at one side-or the other of the vertical line through thestring of suspension insulaters, not shown, supporting the same, the boltlv will play over the intermediateportion 18 of each of the slots-11 in the suspension links, vand nothing willhappen. A 1f, however,` the result of the accumulation of sleet or .ice upon the conductor at one side vof the string ,of insulators, or the tower supporting the same, there should be any tendencyto pull 'the string laterally,.the'inovement of the be. When this occ-ursit is anparentthat the coaction of the bolt 16 witheither pair of end portions 19 oft-he cam slotsfwill force the members 1 land 2' apartand permit the conductor 4 to slip through untill an'equilibe rium in the conductor line at opposite sides of the tower, or-string ofk insulators and Clamp is ylrJlorught about. f- The formof the invention disclosed in Figure`s4, V5 and V(iis slightly different from wha-thas been abovedescribed few parf ticula-rs, especially in that means is provided for 'varying' the degree cf'l'clamping action for ytakingl up Wear resulting from the inevitablemovem'ent'of the parts'f'j" f i i' Y Referring yto these three "-figures -in detail,

the numerals 21 and 22 represent the upper and'lower clamping members channeled or otherwise formed to provide seats 23 for the conductor 24C. Instead of having the lugs 5 and` 6 arranged as in the first described form 'of the invention, the members 21 and 22 are shown as provided, each at one side, with a lug 25 received within a recess 26 in the other member. By this arrangement it will be apparent that the members 21 and 22 are interchangeable or reversible in the same sensel as theV members 1 and 2, the only difference being in the exact arrangement of cooperating lugs which prevent relative longitudinal movement of the members in service.

In the modification, the suspension means is shown as comprising a yoke 27 apertured at 28 and adapted for connection with a pin or the like at the lower end of a string of insulators such, for instance, as by means of the pin 9 shown in Figure 2. Instead of considering the member 27 yas a yoke connected at its lower end bly the integral bight portion shown' it might be construed as comprising pair of links rather similar to the links 7 but rigidly connected at their lower endsin a manner equivalent to the integral bight. rflue sides of the yoke are formed intermediate their ends with caml slots 29 corresponding to the slots 19 for the passage of a bolt'SO corresponding` to the bolt 16. As the members 21 and 22 are counterpart each `is formed with a hole 31 so that regardless of which one is uppermost means is provided for the reception of the-bolt 30. It should also be noted that the lugs 25 and recesses 26 at the opposite sides of the members 2,1 and 22 are alternately arranged so as to permit the reversal or interchangeable arrangement ofthe members 21 and 22. Of course .these elements operate in the same manner as the lugs 5 and 6 of the irst described form'.

The means in this instance for effecting a positive engagement of the members 21 and 22 ywith the conductor, is shown as comprising a stud or set screw 32 which is threaded through the lower solid end of the yoke, or of whatever means connects the side of the yoke, and which has a preferably curved or spherical end 33 engaging within a recess Sil. If the members 21 and 22 are made counterpart, which is of course not essential, it is intended that-both be` provided with a recess 34- so that either one may be the bottom.

Infthe operation of both forms it is apparent that the-action is fundamentally thesame inasmuch as the clamping members will be maintained in close engagement upon the conductor as long as the suspension means is in upright or only-slightly inclined position with respect to the assembled clamping members. This is 'true owing to the fact that the centerof the lower surfa ce or wall or each of the cam slots in the suspension links or yoke is concentric with the bolt 12 in one instance or the engagement of the set screw 32 within the recess 34 in the other instance. rIhc sccond mentioned form of the invention has thc advantage over the first form in that the set screw provides an adjustment not only for initially varying the degree of the clamping action but also for taking up any wear which mioht occur in the cam slots as the resultof play of the string of insulators back and forth with respect to the clamping means. The material between the unoccupied hole 3l in the clamping member 32 and the recess 3d is suficiently thick that there is no possibility of crushing through even though a very severe strain be applied. The lock nut shown at in Figures Il and 5 is simply for the purpose of preventing accidental unscrewing of the set screw.

From the foregoing description and a study of the drawings it will be apparent that I have thus provided a very efficient conductor clamp which will be positive in that no reliance is placed upon spring tension for either clamping or releasing purposes, a positive holding action and also a positive release being effected by cam action. Means has been provided for adjusting the grip and also for taking up any wear which, though unexpected and improbable, might by any chance develop. By making the clamping members counterpart it is apparent that the number of necessary parts will be reduced to the minimum, there being actually only three or four aside from the necessary bolts. On account of this extreme simplicity the cost of production should be very slight and as the parts do not have any relative movement under ordinary circumstances durability should be certain. It is believed that the construction, operation and advantages will be readily apparent to one skilled in the art without further explanation.

lVhile I have shown and described the preferred embodiment of the invention, it should be understood that the disclosure is merely an exemplitication of the principles involved as the right is reserved to make all such changes in the details of construction as will widen the field of utility and increase the adaptability of the device provided such changes constitute no departure from the spirit of the invention or the scope of the claims hereunto appended.

Having thus described the invention, I claim:

1. A device of the character described comprising a plurality of clamping members adapted to be engaged upon a conductor, suspension means connected with said clamping members as an assembly, and cam slot means for maintaining the clamping members in clamping relation to the conductor.

2. A device of the character' described ISO ing relation to the conductor and means other 'thanithe tension oi the conductor for moving the clamping members apart upon swinging of 'the suspension means with respect thereto.

3. A device oi: the character described comprising a plurality of clamping members adapted toabe 'engaged upon a conductor, suspension means pivotally connected witlisaid members, cam means coopera-ting with the suspension means and clamping members forV maintaining the clamping relation, and other cam means operative upon swinging movement of thesuspension means with respect to the clamping means for releasing the latter.

4. A deviceot the `character described comprising a pluralityo'f clamping members adapted to be engagedupon a conductor, suspensionnieans pivotally connected with said'members,1cain means cooperating with the suspension means and clamping members for maintaining the clampingV relation, and other caninieans operative upon swinging movement of the suspension vmeans with respect tothe clamping means for releasing the latter, said clamping members being reversible and interchamgeable.

5. A device V.of the character described comprising aplurality oi clampingmenibers adapted to be engaged v.upon a conductor, suspension means pivotally connected with said members, cam means cooperating with the suspension means and clamping inembers for maintaining` the clamping relation,

i and other cam means operative upon swinge ing` movementrof the suspension. means with respect to the clampingineans. ior releasing the latter, vsaid clamping members being counterparts. Y Y Y y '6. A. device. of" the .character described comprising a plurality "of clamping members Vadapted to beeneaged upon a conductor, suspension means pivotally connected with said members, camy means cooperating Vwith the suspension means and clamping niembers for maintaining the clamping relation,

other cam means operative upon swinging movement of the suspension means witlirespect to the clamping means for releasing the latter, and cooperating means formed on the clamping members for reventino rela- .b Y i. f ri tive longitudinal movement thereofjJ-and guiding thersame during release thereof. f

.--idevice of the character described comprising ay pluralityof clamping members adapted tobe engaged v upon a conductor, suspension means f pivotally connected i with isaidmeinbers, camineans cooperating with the suspension vmeans and clamping members for maintaining the clamping relation, other ,'cam means operative upon swinging movement of the suspension meansA with respect to theclamping means for releasing the latter, and means on the clamping-members for'pre'- venting relativelongitudinal moveinentthereof, said vlast named means operating also to guide said'clamping members -duringseparait-ing movement and Acoifnprising intericit ting-lugs. y c 1 8.oA device of the character described comprising the combination of avplurality of clamping members adapted for engagement upon a conductor, suspension means pivotally connected with one of the clamping members, and cam means connecting the suspension means with the other of said elampingmeinbers for normally maintaining the clamping members in clamping relation to the conductor and formforcing them apart upon they occurrence of relative swinging movement ot the suspension means and clamping means beyond a. predetermined eX- teiit. A V SLA device of the character described Vcomprising a plurality of .clamping members adapted for engagement upon a conductor at the top andV bottom thereof, suspension means straddling both clamping members and pivoted' to the lower one thereor, cam means on the suspension means, and means projecting laterallyv beyond the upper clamping member'cooperating with said cam means for normally maintaining the clamping` members in clamping relation to the conductor. Y

l0. A' device of the character described comprising the combination of -a plurality of clamping members adapted for engagement upon a conductor, suspension means Vpivotally vconnected withY one of the clamping mem-bers, cam means connecting the sus-g pension mea-ns with the other of saidV clamping membersV for vnormally lmaintaining. the clamping members in [clamping relation to the conductor, means other than the conductor vfor forcing the clamping members apart for rendering them ineective upon the oc'currence'oi relative swinging movement of the suspension means and clamping means beyond a predetermined extent, and means for adjusting the clamping members relatively Ato each other to `vary the grip on the conductor. y

11. Avreleasing clamp comprising upper and lower clamping members adapted for en gagement vupon a conductor,y suspension Vmeans 'straddling both clamping members n upper clamping niember,and said arms being i'orined with cani slots cooperating with'said .transverse element for normally maintaining the clamping members in clamping relation tothe conductor.

12. A releasing clamp comprising upper and lower clamping members adapted for engagement upon a conductor, suspension means straddling both clamping members and including spaced arms, a pivot element passing through the lower portions of said arms and through the lower clamping member, a transverse element carried by the upper clamping member, and said arms being formed with cam slots cooperating with said transverse element for normally maintaining the clamping members in clamping relation to the conductor and for forcing them apart upon movement of the suspension means beyond a predetermined position with respect thereto, said cam slots having portions concentric with said pivot element to maintain the clamping relation throughout limited movement of the suspension means.

13. A releasing clamp comprising upper and lower clamping members adapted for engagement upon a conductor, suspension means straddling both clamping members Y arms and through the lower clamping me-m ber, a transverse element carried by the upper clamping member, and said arms being formed with cam slots cooperating with said transverse element, said cam slots having curved portions concentric with the pivot element coacting with said transverse element for maintaining the clamping action of the clamping members throughout limited relative movement ofthe clamping members and 'suspension means and having other portions curved oppositely forrcoaction with the transverse element to force the clamping members apart upon relative movement of the suspension means and clamping members beyond a predetermined relative position.

14. A releasing clamp comprising upper and lower clamping members adapted for engagement upon a conductor, suspension means straddling both clamping members and including spaced arms, a pivot element passing through the lower portions of said arms and through the lower clamping member, a transverse element carried by the upper clamping member, said arms being formed with cam slots cooperating with said transverse element :tor normally maintaining the clamping relation of said clamping members ing the lower clamping member for adjusting the same with respect to the upper clamping member.

15. A releasing clamp comprising upper and lower clamping members adapted for engagement upon a conductor, a suspension yoke straddling both clamping members and rockably supporting the lower one thereof, each clampingmember having a recess and a projection whereby the recesses and projections will cooperate to prevent relative longitudinal movement of the clamping members, coacting means on the yoke and upper clamping member for normally holding said clamping members in clamping relation upon the conductor, and cam means on the yoke and upper clamping member for forcing the clamping members apart upon the occurrence of swinging movement of the yoke with respect thereto beyond a predetermined extent.

16. In a releasing clamp, upper and lower clampingmembers adapted for engagement upon a conductor, a suspension yoke straddling the clamping members and having a closed lower end or bight portion, means eX- tending through said bight portion constituting a fulcrum for the lower clamping member, and cam means on the yoke and upper clamping member operating normally to maintain the clamping members in clamping relation upon the conductor and also operable to force the clamping members apart.

17. In a releasing clamp, upper and lower clamping members adapted for engagement upon a conductor, a suspension yoke straddling the clamping members and having a closed lower end or bight portion, means eX- tending through said bight portion constituting a ulcrum for the lower clamping member, and cam means on the yoke and upper clamping member operating normally to maintain the clamping members in clamping relation upon the conductor and also operable to force the clamping members apart, said fulcrum means being adjustable for moving the lower clamping member with respect to the upper independently of the action of said cam means.

18. A suspension clamp device, comprising clamping members engageable upon a conductor, suspension means for the clamping members, and cam means connecting the suspension means and the clamping members for normally maintaining the latter in clamping relation to the conductor and for positively moving them apart upon relative movement of the suspension means and clamping means beyond a predetermined extent.

In testimony whereof I aflix my signature.

JOHN MILTON JESTER. 

